The present invention relates to quickfit methods, fittings and apparatus for connecting pipes and pipe elements.
The present invention relates to pipes for carrying water and the like and, in particular, it concerns methods for connecting pipes and the corresponding pipe elements and connections.
Various techniques are known for connecting water pipes in fire prevention and domestic water supply systems. For many years, the only alternative to threading or flange connections was a labor intensive welding processes. More recently, a number of quick-assembly systems have been marketed. These systems seek to reduce the labor costs of assembly by providing various types of mechanical engagement to hold pipe ends together without requiring welding.
One quick-assembly system, disclosed in U.S. Pat. No. 5,040,831, is available commercially in the U.S. under the trade name POZ-LOK® from Southwestern Pipe, Inc. This system employs specially molded connector fittings which have slots on opposite sides. A pipe is inserted into the connector and a U-shaped bracket is hammered in through the slots. The bracket creates indents in the sides of the pipe, thereby retaining the pipe within the connector.
Another system is proposed by U.S. Pat. No. 5,779,283 to Kimura et al. This system is similar to the POZ-LOK® system, but uses a “key” member inserted in a channel formed in a connector on just one side of the pipe. The key member is disclosed as either a flat plate with a raised ridge or as a round pin. In the case of the round pin, the front of the pin is formed with a threaded section for fastening after insertion by use of a nut on the opposite side of the connector.
In order to produce a quick-fit system with lower production costs, a number of systems use thin-walled connectors that can readily be produced from modified sections of standard piping. An example of such a system is commercially available in the U.S. under the trade name PRESSFIT™ from VICTAULIC®.
The PRESSFIT™ system employs a thin walled connector with an internal O-ring seal positioned around the end of a pipe. Engagement of the pipe within the connector is achieved using a special hydraulic circumferential press tool that makes a circumferential indent around the joint through both the connector and the pipe, thereby permanently fixing them together.
My U.S. Pat. Nos. 5,927,763 and 6,634,677 disclose a method for connecting a first end of a cylindrical pipe within a bore of a pipe element having a terminal portion having an internal diameter sufficient to receive the first end. In this method, the wall of the terminal portion of the pipe element is outwardly deformed to produce an approximately linear, open-ended channel in a direction roughly tangential to the internal surface of this terminal portion. The first end of the pipe is then positioned within the terminal portion, and a pin-like element is forced along the channel. This causes local inward deformation of the first end, thereby locking the first end and the pipe element together.
These improvements notwithstanding, the present inventor has recognized a need for improved quick-fit methods and devices for connecting pipes, and the subject matter of the present disclosure and claims is aimed at fulfilling this need.